The handbook or information materials provided to you during the PDOS will include some information on applicable labour laws. Some of these are country or region specific such as the regulations on iqama and sponsorship or kafala, exit clearance, and non-transferability to other employers.
For more information, you may check these websites and regularly contact the MRC if there are questions or additional information needed:
https://mlsd.gov.sa/en/procedures (Kingdom of Saudi Arabia)
https://government.ae/en/information-and-services#/ (United Arab Emirates)
https://www.onlineqatar.com/living/laws-and-regulations/labour-laws-in-qatar (Qatar)
https://qatarlaborlaw.com/ (Qatar)
http://www.mylabourlaw.net/ (Malaysia)
http://www.koreanlaborlaw.com/ (South Korea)
http://www.mybahrain.net/info/visit-visa-information.aspx (Bahrain)
https://www.labour.gov.hk/eng/legislat/content2.htm (Hong Kong)